488 



Scientific Proceedings, Royal Dublin Society. 



To ascertain whether bituminous substances were present, the 

 crushed mineral was treated with pure alcohol, which was first 

 proved to leave no residue on evaporation. The liquid was filtered, 

 the filtrate evaporated to dryness, and a light-brown residue 

 obtained. A portion of this was moistened with a drop of hydro- 

 chloric acid, and an addition of ammonium chloride, ammonia, 

 and ammonium oxalate yielded a precipitate of calcium oxalate. 

 Another portion, treated with nitric acid and subsequently with 

 barium chloride gave a precipitate of barium sulphate. A similar 

 result was obtained by treatment with pure ether. In neither 

 instance was any organic matter dissolved. These extracts by 

 alcohol and ether prove the existence of calcium sulphydrate in the 

 mineral ; hence the odour when the mineral is broken. The ana- 

 lytical numbers are the following : — 



Mean of three determinations. 



